Climate change and water: Adaptation

Climate change and water: Adaptation Stewart J. Cohen and Roger S. Pulwart y Abstract In many parts of t he world, climate change is anticipat ed t o result in great er water scarcity. Fut ure adapt ations may include technical changes that improve water use efficiency, demand mana gement (e.g. through metering and pricing), and institut ional changes t hat improve t he tradabilit y of wat er right s. The avail ability of wat er for each t ype of use may be affected by ot her compet ing uses of the resource. Consequently a complete analysis of t he effect s of climate change on human water uses would consider cross-sector interactions, including the impact s of changes in water use eff icien cy and int ent ional t ransfers of t he use of water from one sect or to anot her. The barriers to implementing adaptation measures include the inabil ity of some natural systems to adap t at t he rat e of combined demographic pressures and climate, incomplet e understanding and quantifying of wat er demands, and impediments t o the flow of timely and reliable knowledge and information relevant for decision makers. M any adaptation measures are t echnology and effici ency based. Early warning informat ion, as well as decision support t ools for long range planning, should be based on a mixed portfolio of experimental and scenario-based approaches for shared learning by researchers and pract itioners. This becomes an integrat ed watershed manage ment approach in which adaptive management is an operational tool for learning. We examine two cases from western North America (t he Okanagan, and Colorado Rivers) t o illustrate mechanisms for int era ctive le arning, anticipatory coordinat ion and communication. Key word: adapt ation, climate change and water, integrated wat ershed management

1. Introducti on Climat e change poses major concept ual challenges to resource managers, in addit ion t o t he challenges caused by population and land use change. As is widely acknowl edged, it is no longer appropriat e t o assume t hat past hydrological conditions will continue into the fut ure. The robust ness of present wat er resources adaptat ions will be test ed under a changing climate. Climate information services design ed t o support adaptation will be import ant in coping wit h current and future climat e ext remes and their effects on wat er resources. Useful informat ion may be available, and can produce posit ive result s, but it s effect ive use for adapt at ion can be overwhelmed by rat es and magnitudes of social, economic and environment al changes.

Climate change and water: Adaptation

Experience shows that: (1) Adaptat ions in many cases are driven by focusing on events that induce crises, learning and redesign, and in which leadership and t he public are engaged, (2) Opportunit ies exist t o learn from adaptive management pract ices that focus on social networking, and (3) Long-t erm scenarios can bring focus on changes in extremes. Adverse effects of climat e change on freshwater sy stems aggravat e t he impact s of other stresses, such as populat ion growt h, changing economic act ivit y, land-use change and urbanization. Critical issues include: (1) ensuring adequate wat er to maintain environment al services that support economic and cultural benefits; (2) ensuring development , adoption and evaluat ion of effi cient t echnologies, and (3) managing informat ion needed to coordinat e dat a collection and qualit y cont rol, which will allow us to t ransform dat a and forecasts int o accessible, credible, and usable infor mation for early warning, risk reduct ion and adaptat ion pract ices in the wat er resources sect or. Increasing demands and aging infrastruct ure int roduce additional concerns. Adaptive measures recommended and employed to date include both demand and supply side app roaches. Examples include: wat er recy cling, r educe irri gat ion demand, water market s, economic incentives including met ering, pricing; conjunctive surface- groundwat er use, increase storage capacity, and desalinat ion. Flexibility in operation systems (reservoirs et c.) in t erms of efficiency and buffers t o climate variations requir es re-exa minat ion of design criteria, operating rules, assumpt ions made from a l imited climate record and at tendant cont ingency planning. The greatest challenges wil l be in mult i-object ive planning and t he informat ion management needed for attendant decision-making processes and for assessing the quality of t hose decisions. Documenting the costs, benefits and tradeoffs in pursuing and secur ing diverse values of river syst ems (e.g. hydropower, environment , irrigat ion, recr eat ion, and aesthetics) are straightforward t asks. As a result , decision-making is very much a process of negotiating accept able outcomes among various int erest s as opposed t o one of simp ly reducing t he uncertaint y of our knowledge of t he physical syst em or increasing t he operating efficiency of designed systems (e.g. dams). We examine t wo cases from west ern Nort h Americ a (the Okanagan, and Colorado Rivers) t o illustrate mechanisms for interact ive learning, anticipatory coordination and communication. These t wo basins offer unique opportunit ies for identifying lessons for strategic learning on the evolution of cross-scale environment al risks over time, t he development of a collaborative framework between research and water resources mana gement , and for guidance on t he development of informat ion services in support of adaptation at t he watershed scale.

2. Cli mate change, water scarcity, and managing for multiple objectives Recent revi ews of the stat e of knowledge on impacts of climate change on water resourc es (Kundzewicz et al., 2007; Arnell et al., 2001) have described the growing risk t hat climat e change will l ead to wat er scarcit y in certain regions of the world. Some semi-arid and subhumid regions, such as Aust ralia and t he Sahel have experienced more intense droughts.

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Aust ralia has responded with several water adaptation strat egies, including drought relief programs, use of recycled wat er, replacement of open irrigation channels t o reduce losses, and desalination (Henessey et al., 2007). The long-term adaptat ion challenge for watersheds experiencing both acut e and chronic wat er scarcity is t he int egration of concurrent driving forces int o planning, design, and operat ion of wat er systems. If water syst ems continue t o be planned with the explicit or implicit assumpt ion of cli mate st ationarity, surprises and conflicts may emerge. Milly et al.. (2008) have proposed that water management frameworks should be adapted t o nonstat ionary climatic and hydrologic variables. This would require r apid flow of information from the scientific realm to water managers and pract it ioners. The need for t his can be illust rated by the example of the Columbia Basin. M odelling studies and surveys of water managers have indicated t hat concurrent changes in observed and projected regional economic development and climate patt erns would affect t he balancing of mana gement objectives, including hydroele ctric product ion, in-st ream flows for aquatic ecosyst ems, irrigation, navigation, flood control, recreation, and domest ic needs (Cohen et al., 2000; Cohen, de Löe et a l., 2004). Barnett et al. (2005) illustrat e how a climate change scenario of earlier snowmelt and lower minimum flows during the summer, superimposed on existing reservoir operat ions, could lead t o 10-20% reductions in hydroelectric production because of the requirement t o prot ect in-stream flows for fish. Ima gine being forced t o choose between hydroelectric product ion and fisheries protection as part of a climate change adaptation strat egy? Climat e change will chal lenge e xisting man agement models that assume st ationarity in climatic and hydrologic indicators. Note that this is not restrict ed to changes in averages. It may be possible that changes in the probability of exceeding certain t hresholds, even without a change in t he aver age, might force the alt eration of operating rules for a water system. A process would therefore be needed to facilit ate the testing of alternat e mana gement frameworks for water systems under various scenarios of climate change and development . This could explicitly include the evaluation of t he effectiveness of individual adaptation measures, and combinat ions of measures.

3. Creating a framework for adapting to climate change Various forcing fact ors can interact wit h each other, creating p roblems of increasing complexit y. M anaging wat er syst ems t o meet multiple objectives requires system knowledge, bot h technical and quant it at ive, as well as experient ial from the perspect ives of planners, user groups, technical experts and governments. This suggests that a combination of quant it at ive modelling and dialogue processes should be explored to see if t hat provides the basis for an evaluation of climat e change problems facing water syst ems (e.g. NeWater p roject —ht tp://www.newater.info). Two main components are needed for t his approach t o be carried out. The research component would be organized as a Participatory Int egrated Assessment (PIA), in which dialogue processes are used as research tools that would complement quant it ative models (Tansey et al., 2002) and visualizat ion (Sheppard, 2005), and indeed could facil it at e t he

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development of decision support models (van den Be lt , 2004). A PIA could enga ge a wide range of local and syst em knowledge holders, as wel l as researchers from various disciplinary backgrounds (Yohe et al., 2007). The implement ation component would be facilitated through “ mainstreaming” in which policies and measures associat ed with climate change are direct ly int egr ated into development planning and ongoing decision making (Klein et al., 2007). M ainst reaming cl imat e change adaptation int o exist ing wat er mana gement systems is being considered in several case studies, but barriers have been encount ered, such as a) gaps in st akeholder part icipation during key phases of project design and imp lementat ion, and b) p ost -disaster pressures to quickly return a system or place to pre-disaster conditions rather that incorporate longer-t erm development policies (Adger et al., 2007). PIA and mainstreaming are not t ypical act ivities within the research and policy communit ies. Informat ion flow from providers of climat e informat ion to policy makers first goes t hrough a t ranslation process. Figure 1A illust rat es one component of t his—t he t ranslation of climate infor mation int o impacts information that would be of interest t o pract it ioners from various fields (such as engineering or public healt h). Figure 1B plac es this within t he lar ger context of multiple flows of information from climate scienc e research and c limate impacts research to pract it ioners and policy makers. The long term sust ainability of these processes depends on whet her t hey can increase local capacity t o serve as champions for them. Climate change adaptat ion is p rimarily a local and regional scale act ivit y, undertaken within a national or internat ional discourse that provides the necessary background for such initiatives to be undertaken. If PIA and mainst reaming can succeed in providing shared l earning experiences for local stakeholders, some of these individuals may become ext ension agents for climate change learning and act ion, in a way t hat researchers and nat ional act ors could not . Subsequent ly , t he roles of researchers and st akeholders would eventually be reversed, and we would begin to see more locally led adapt ation initiat ives, in which researchers and national actors would serve as resources support ing local champions.

4. Case studies—Colorado and O kanagan Basins The Colorado and Okanagan B asins are semi-arid regions in western North America. The Okanagan is a smal l sub-watershed wit hin the Columbia Basin. In this sect ion, we describe e xperiences wit h applying PIA in t hese two cases. Case stu dy: The Colorado River The Colorado River (Figure 2) supplies much of t he water needs of seven US states, two M exican states, and t hirty-four Native American t ribes (Pulwarty et al., 2005). These represent a population of 25 million inhabitants, with a projection of 38 million by the year 2020, which receive at least some part of their wat er from t he Colorado. In only 80 years, t he population of t he seven Colorado R iver basin states has increased by 800 percent , adding 44 million people. Nevada, Arizona, and Colorado, all in the Colorado River basin and heavily dependent on Colorado River wat er for municipal and agricultural uses, were t he fastest growing st at es in t he nat ion between 1990 and 2000. About 12 mi llion residents

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live along the border, a number projected to as much as double (t o 24 million) by 2020 (Bennet t and Herzog, 2000).

Fi gure 1. A) Flow of cl imate change information to practitioners (upper panel), B) Additional pathways for climate information to reach decision makers (lower panel). Source: Cohen and Waddell, in press. The expansion of population and economic activit ies across the western U.S. , and concurrent responses to drought event s, have resulted in significant st ructural adapt ations, including hundr eds of reservoirs, irri gat ion projects and groundwater wit hdrawals, being developed in semi- arid environments. As widely document ed, t he allocat ion of Colorado River wat er to basin stat es occurred during t he wett est period in over 400 years (i.e., 1905– 1925). The result ing complexit y is that decisions on t he Colorado Basin cross several t emporal and spatial scales (see Tabl e 1). The Colorado Basin is also home to one of the longest running adapt ive environment al assessment and management programs in t he country (Pulwarty and Melis, 2001).

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Only a small portion of the full Colorado Basin area (about 15%) supplies most (85%) of its flow. The Colorado syst em has experienced below aver age condit ions in 7 of t he last 9 years. Unt il t he last few years, t he expectat ion of Colorado River managers was that significant shortages in t he Lower Basin would not occur unt il aft er 2030. Natural inflows into the basin have been poor for several years: 62% of the 30-year average in 2000, 59% (2001), 25% in 2002, 51% (2003), 49% (2004), 105% (2005), 71% (2006), 68% (2007) and 105 (projected for 2008). The region has also experienced a 0.8o C rise in t emperature over the past 50 years, which has result ed in increasing losses of snowpack exacerbating drought conditions through evaporat ion, vegetat ion st ress, wat er demands, reduced soil moisture. It is estimated that 12-15 years of average con ditions (based on the past 100 years) are needed to rest ore the basin to pre-2000 levels. This recent experience il lustrat es t hat ‘critical’ conditions already exist in t he basin (Pulwarty et al., 2005). Con formato: Inglés (Reino Unido)

Fi gure 2. Colorado River Basin. Estimates from 12 AR4 models show t hat , with increased warming and evaporat ion, concurrent runoff decreases could reach 20% by 2050 and 30% at the end of 21st century (Milly et al., 2005). Under such condit ions, toget her with projected withdrawals, t he requirements of the Colorado River Compact may only be met 60–75% of t he time by 2025 (Christ ensen et al., 2004). Some studies estimate that, by 2050, t he average moisture conditions in the south-west ern USA could equal t he conditions observed in t he 1950s.

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Such changes could oc cur as a consequence of increased temperatures (t hrough increased sublimat ion, evaporation and soil moisture reduction), even if precipitat ion levels re main fairly constant. Some researchers argue that t hese assessment s, because of model choice and assumed adapt ations, may actually underestimate future declines. By 2004, t he drought began t o overwhelm planning assumpt ions derived from previous projections of impacts from analogues of hist orical e xtremes. Flawed demand estimates, especially induced during drought , were key to these divergent out comes. The resulting awareness was that climat e change, t oget her with increasing development pressures, would result in drought impacts that are beyond t he institutional experience in t he region and would exacerbat e conflict s among water users. In De cember 2007, new guidelines establishing rules for shortages were int roduced by the U.S. Secretary of the Interior (USDoI, 2007), specifying who will acc ept reduct ions and when t hey take t hem. This is essential for prudent wat er planning in t imes of drought and included new operational rul es for coordinat ed operation of Lake Powell and Lake M ead (t he two largest reservoirs in t he U.S.), encouraging new initiat ives for wat er conservation and t o begin a process of explicitly incorporating the role of climat e change int o planning and operations. The guidelines provide a mechanism that encourages water conservat ion in Lake Mead in t he Lower Basin to minimize t he likelihood and severity of pot ent ial fut ure short ages t hrough 2026. Water managers in Colorado Basin st at es are explicit ly considering how t o incorporate t he potent ial effect s of climate change int o specific designs and multi-stakeholder set tings. Early warnings of changes in the physical and social systems and of t hresholds or critical points t hat affect int egrat ed mana gement (wat ershed, coast al etc.) p riorities become import ant . One such innovat ion the National Integrat ed Drought Information System (www.drought.gov) was signed int o U.S. Public Law (109-430) in 2006. NIDIS is t he direct result of t he Co lorado B asin drought discussions at t he state level and project ions of future conditions resulting from cli mate change. It coordinates previously independent systems of informat ion providers, users, and organized interests on monitoring and forecast ing, drought risk and impacts assessment s, and communicat ion and preparedness planning. M ost decision makers engaged in cooperat ive strategies addr essing wat er scarcit y have repeatedly st ated the need for integrated mana gement of e xisting supplies and infrast ructure (Pulwarty, 2003). What is dist inctive about the Colorado is that t he inclusion of stakeholders in water management policy has become t he norm. However, regardless of how robust civil-society institutions may be, severe drought (or flooding) can expose underlying institut ional barriers to effective cooperat ion. Thus for large river basins the goal should not be to reify some part icular scale of analysis (e.g. local, regional) but to uncover what is needed at each of t hese scales and t o address impediments and opport unities to t he flow of informat ion and innovations between t he decision making nodes. Case study: The Okanagan A case study on t he implications of cli mate change for wat er management in the Okana gan region of British Columbia, Canada, i llust rat es a communications pathway designed to

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t ranslate long term globa l climat e change scenarios int o loca l water management risks, and t o lay the foundation for const ructing a decision support tool for the Okanagan watershed. The app roach t aken was to organize and maint ain a PIA, in whi ch researchers and local experts shared informat ion and perspectives on various aspects of this long-t erm issue (Cohen, Neilsen and Welbourn, 2004; Cohen et al., 2006; Cohen and Neale, 2006). The Okanagan is a semi-arid r egion in sout hern Brit ish Columbi a (Figure 3). In 2003, t he region e xperienced a drought with accompanying forest fires which dest royed homes in several communities (Filmon, 2003). A gainst t his background of increased awar eness of t he effect s of climat e ext remes, increasing local att ent ion was directed at a climate change impact s and adaptat ion study t hat had been init iat ed in 1999, and was evolving int o a PIA. The first step was t o apply a set of climate change scenarios to a hydrology model calibrated for the Okanagan (Cohen et al., 2004; Merritt et al., 2006).

Fi gure 3. Okanagan Basin (from Cohen et al., 2004). The resulting hydrographs (Figure 4) became an important communications mechanism linking global cli mate change to impacts on st reamflow in t erms well understood by local wat er professionals and major users groups. The message from t his step was that climat e change would lead to earlier seasonal peak flow due to ear lier snowmelt, and t his would result in a longer minimum flow period during the growing se ason. Tot al annual streamflow would also decrease from historic averages. Local water supplies largely consist of many small reservoirs which capt ure and store spring snowmelt for release t hroughout t he year. How would reservoir management adjust t o scenarios of climat e change and population growt h? The climat e change scenar ios were applied to a crop wat er demand model developed for local conditions. Projected changes in crop water demand were compared with scenario changes in water supply to det ermine potential changes in the frequency of high risk years, i.e. years with low supply and high demand (Figure 5). At t he same t ime, scenarios of domestic water demand were also constructed, incorporating potential changes in climate,

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population, and implementat ion of demand side management opt ions (Neale et al., 2007). Throughout the process of scenario construct ion, local water professionals and int erests (e.g. irri gat ors, habitat prot ect ion groups, aboriginal communities, municipal governments, and regional planners) were partners in a shared learning process wit h t he research team. This laid the foundat ion for moving beyond t he scenarios themselves towards creat ing a decision support tool, the Okanagan Sust ainable Water Resources M odel (OSWRM), which could be used t o explore various long-t erm response opt ions within scenarios of climate change and population growt h. This group-based approach t o model

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Figure 4. Ok anagan hydrology scenario, based on the CGCM2 -- A2 cl imate scenario; example from Whit eman Creek (Merritt et al., 2006). const ruction combined local knowl edge and scenar io output s, using a STELLA TM plat form to offer a tool for deskt op experimentat ion of various combinat ions of scenarios and response options (Langsdale et al., 2007). Results from ot her study components provided important inputs for OSWRM (Cohen and Neale, 2006). One of t he results from t he first version of OSWRM is t hat an adapt ation portfolio of water demand mana gement measures would only part ially offset t he increasing frequ ency of wat er deficit conditions (Table 2). The overall reliability of t he Okanagan syst em t o meet demand decreases from a historic rat e of 98% t o 72-82% in t he 2050s, wit h climate change being the major cause of t his decrease (Langsdale et al., 2007), as illustrated by comparison wit h t he ‘no climat e change’ scenario. Expansion of supplies through greater use of t he region’s lakes may be feasible, but it will be a difficult task t o avoid depleting t he resource, as well as to pay for the addit ional costs of dist ribution and wat er treat ment . This will become an important challenge for long term wat er governance and sustainable development in the region (Cohen and Neale, 2006).

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Fi gure 5. Scenario changes in balance betwe en water supply and crop water demand, Okanagan – example from Trout Creek for HadCM3 – A2 climate change scenario (Neilsen e t al., 2004, 2006). Table 2. Number of years out of 30 where water demand equals or exceeds water supply in the Okanagan Basin, assuming high population growth scenario (Langsdale et al., 2007). Moderate adaptation scenario includes expanded use of residential demand management, inc luding metering with pric es charged at increasing b lock rates, public education, and reduction of agricul tural demand by 6% through improved water use efficiency. SCENAR IO

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OSWRM is not a “forecasting” model, however, and one of the cont inuing communications challenges is t o ensure consist ency in descript ion of what t his t ool, and ot her decision models, can and cannot do. This too is part of the shared learning experien ce. It is hoped t hat local part icipants in t his process will become communications partners, providing local context for broader public discourse about climate change effect s and response options in the Okanagan region. Increased awareness of potent ial future wat er supply problems led the region’s wat er authority, t he Okanagan Basin Water Board,

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t o init iate a major assessment of t he basin’s wat er balance (www.obwb.ca ). Also, a regional planning aut horit y explicit ly included cl imat e change scenarios in a water mana gement plan for one of the sub-basins (Summit Environmental, 2004). 5. Concl usi ons A major challenge in t he coming decades, given commit ted climate change already in t he system, will be maint aining water supplies for environment al services, which support economi es t hroughout t he United St ates and Canada. There are signif icant barriers to implementing adapt at ion in complex sett ings. These barriers include t he inabil it y of nat ural systems t o adapt at t he rat e and magnitude of change, as wel l as cognit ive, behavioural, social and cult ural constraint s. There are also significant gap s in knowledge for adapt at ion, as well as imp ediments to flows of knowledge and informat ion relevant for decision makers. In addition, t he scale at which reliable informat ion is produced (i.e. global) does not always mat ch with what is needed for adaptation decisions (i.e. watershed and local). The mana gement of t he cumul ative impacts of e xtremes (droughts, floods, hurricanes et c.) usually occurs t hrough react ive, crisis-driven approaches. The Colorado River Basin experien ce shows that change in managing climate-re lat ed risks (in this drought) may be most readily accomplished when: (1) a focusing event (climatic, l egal, or social) occurs and creates widespread public awareness; (2) leadership and t he public are engaged; and (3) a basis for int egr ating research and mana gement is est ablished. As the Okanagan case and others (see Pulwarty and M elis, 2001) show, a key component in developing such an int egrated framework is t he ability of practitioners themselves t o manipulat e data and to reconc ile scient ific cl aims wit h t heir own knowledge. This plays import ant roles in t heir choices. There is a st rong need for the inquiry int o, and development of, int eract ive approaches between decisive (policy and operat ions) and nondecisive (research) part icipants to t ake advant age of new opportunit ies as systems evolve. Long -t erm cumulat ive environment al p roblems can seldom be dealt with by single discret e actions or policies but respond only to continuing, sustained efforts at learning, supported by st eady public att ent ion and visibility. Even where informat ion on thresholds is available, usable and can produce positive result s, t he value of such informat ion may still be overwhelmed by rates and magnit udes of social, economic and environment al changes. There is also the danger of disempowerment of st akeholders if engagement in PIA does not result in actions consistent wit h the assessment ’s findings (Yohe et al., 2007). If lessons learned are t o be actually applied, t hen a lar ge part of t he scientific adaptation goal should be t o inform processes t hat can decrease impediment s to the flow of informat ion and innovations. One example of a program that links an understanding of t he policy contexts (as elucidated in the Colorado case) wit h supporting a dynamic di alogue between researchers and pract it ioners (as in t he Okanagan case) is the NOAA Regional integrat ed Sci ences and Assessments Program (Pulwart y et al, 2009). The RISA efforts show t hat enabling successful informat ion int ervent ions at any point in time requires a critical mass of accessible, credible, and legit imat e information It also requires t he capacity to apply knowledge and evaluat e consequences of its use. This would ent ail: (i) Clarification of

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mana gement goals at the human-environment interface, and (ii) Construct ion of a cooperative foundation bet ween research and management to dist il lessons from comparative appraisals of current and past pract ices, and to develop effective participatory processes t o ensure validity and accept ability of projections of changes in relevant system outputs i.e. robust information in practical cont ext s. Develop ing such an int egrated basis for managing water resources as climate changes requires a mixed port folio of approaches, including: • • • •

•

Mechanisms for ant icipat ory coordination within development plans (e.g. adaptive manage ment wit hin integrated wat ershed and coast al zone plans). Developing usable cli mate risk mana gement triggers for early warning of pot ent ial conflict s in agricult ure, water, energy, healt h, environment , and coastal zones. Developing and employing wat er efficient t echnologies. Actively engaging communities and states in mainst reaming climat e informat ion into practice though part icipat ory mechanisms, such as the co-development of scenarios that link climat e and development goals. Invest ing in career opp ort unities for climat e change adapt ation wit hin local government s and water-based utilities, integrat ed within long-t erm planning for sust ainabilit y.

Fut ure needs include great er exploration of alternat e integration models and overlying policy structures that could, together, facilitate and sust ain shared learning of climate change adaptation. This would ult imately t ransform this from a project-based activity to a long-term service. A complement ary need would be for bett er understanding of communication for cross-scale adaptat ion decisions that may emer ge within one level of government, multi-levels of government , and at t he wat ershed scale with it s mix of governments and utilit ies. This would help t o maint ain institutional memory of climat e change adapt at ion, t hereby improving adaptive capacity as we face the chall enge of mana gin g wat ersheds in the face of climate change. References Adge r, W.N., S. Agrawal a, M.M.Q. Mirza, C. Conde, K. O’Brien, J. Pulhin, R. Pulwarty, B. Smit and K. Takahashi, 2007: Assessment of adaptation practices, options, constraints and capacity. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Work ing Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, M.L. Parry , O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge Universit y Press, Cambridge, UK, 717-743. Arne ll, N., C. Liu, R. Compagnucci, L. da Cunha, K. Hanaki, C. Howe, G. M ailu, I. Shiklomanov and E. Stakhiv. 2001. Hydrology and water resources. In: Climate Change 2001: Impacts, Adaptation, and Vulnerabili ty. Contribution of Working Group II to the Third Assessment Report of the Intergovernmental Panel on Cl imate Change [McCart hy, J., O. Canziani, N. Leary, D. Dokken, and K. White (eds.)]. Cambridge University Press, Cambridge, Unit ed Kingdom and New York, NY, U SA, 191- 233.

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Barnett, T.P., J.C. Adam and D.P. Lettenmaier. 2005. Pot ential impact s of a warming climat e on wat er availabilit y in snow-dominat ed regions. Nature, 438, 303-309. Benne tt, V., and L., Herzog, 2000: U.S.-Mexico Borderland Water Conflicts and Institut ional Change: A Commentary. Natural Resources Journal, 40, 973-989 Chri stensen, N.S., Wood, A.W., Voisin, N., Lett enmaier, D.P. and R.N. Palmer, 2004: Effect s of Climat e Change on t he Hydrology and Wat er Resources of t he Colorado River Basin, Climatic Change, 62, 337-363. Cohen, S . and M . Waddell in press. Climat e Change in t he 21st Cent ury. M cGill-Queen’s University Press, Montreal. Cohen, S . and T. Neale (eds.). 2006. P art icipatory integrat ed assessment of wat er manage ment and climate change in the Okanagan Basin, British Columbia. Final report , Project A846. Submit ted t o Nat ural Resources Canada, Ot tawa. Environment Canada and University of British Columbia, Vancouver, 188p. Cohen, S ., D. Neilsen and R. Welbourn (eds.). 2004. Expanding t he dialogue on climat e chan ge & water management in the Okanagan Basin, Brit ish Columbia. Final Report , Project A463/433, submitted to Climat e Change Act ion Fund, Natural Resources Canada. Environment Canada and Universit y of British Columbi a, Vancouver, 230 pp. Cohen, S ., D. Neilsen, S. Smith, T. Neale, B. Taylor, M. Bart on, W. Merritt , Y. Alila, P. Shepherd, R. McNeill, J. Tansey, J. Carmichael and S. Langsdale. 2006. Learning with Local Help: Expanding the Dia logue on Climat e Change and Wat er Management in the Okanagan R egion, Brit ish Columbia, Canada. Climatic Change, 75, 331-358. Cohen, S ., R. de Löe, A. Hamlet, R. Herrington, L. Mortsch, and D. Shrubsole. (2004). Int egrat ed and Cumulative Threat s t o Water Availability. In “Threats t o Water Availabilit y in Canada”, Environment Canada, National Water Resear ch Inst it ute, Burlington Ontario, 117-127. Cohen, S .J., K.A. Miller, A.F. Hamlet, and W. Avis. 2000. C limate change and resource manage ment in t he Columbi a River Basin. Water International, 25, 2, 253-272. Fi lmon, G. and review team. 2004. Firestorm 2003 – Provincial Review. Submitt ed to the Government of Brit ish Columbia by the Firestorm 2003 Provincial R eview Team (G. Filmon, Chair). Available at : http://www.2003firest orm.gov.bc.ca/firest ormreport /Firest ormReport.pdf Hennessy, K., B. Fitzharris, B.C. Bat es, N. Harvey, S.M . Howden, L. Hughes, J. Salinger and R. Warri ck, 2007: Australia and New Zealand. Climat e Change 2007: Impacts, Adaptation and Vulnerabilit y. Contribu tion of Working Group II to the Fourth Assessment Report of the Int ergovernmental Panel on Climate Change, M .L. Parry, O.F. Canz iani, J.P. Palut ikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 507-540. Klein, R.J.T., S. Huq, F. Denton, T.E. Downing, R.G. Richels, J.B. Robinson, F.L. Toth, 2007: Inter-relat ionships between adaptation and mitigation. Climate Change 2007: Impacts, Adaptation and Vulnerabilit y. Contribut ion of Working Group II to the Fourth Assessment Report of the Intergov ernmental Panel on Climat e Change, M .L. Parry , O.F. Canz iani, J.P. Palut ikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 745-777. Kundze wi cz, Z.W., L.J. M at a, N.W. Arnell, P. Döll, P. Kabat , B. Jiménez, K.A. Miller, T. Oki, Z. Şen and I.A. Shiklomanov. 2007. Freshwat er resources and their mana gement . In: Climate Change 2007: Impacts, Adaptat ion, and Vulnerabilit y. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on

13


Climate Change [P arry, M., O. Canziani, J. Palutikof and P. van der Linden (eds.)]. Cambridge Universit y Press, Cambridge, United Kingdom and New York, NY, U SA, 173-210. Langsdal e, S .M., A. Beall, J. Carmi chael, S. Cohen, and C. Forster. 2007. An exploration of water resources futures under climat e change using syst em dynamics modeling. Integrated Assessment Journal, 7, 1, 57-79. Merri tt W., Y. Alil a, M. Barton, B. Taylor, S. Cohen and D. Neilsen. 2006. Hydrologic response to scenarios of climat e change in subwat ersheds of the Okanagan Basin, British Columbia. Journal of Hydrology 326, 79-108. Milly, P. C. D., K. A. Dunne, and A. V. Vecchia, 2005: Global pat tern of t rends in streamflow and wat er avail ability in a changing climate. Nature, 438, 347-350. Milly, P.C.D., J. Bet ancourt , M. Falkinmark, R.M. Hirsch, Z.W. Kundzewicz, D.P . Lett enmaier and R.J. Stouffer. 2008. Stat ionarity is dead: whither water management ? Sci ence, 319, 573-574. Neal e, T., J. Carmichael and S. Cohen. 2007. Urban Wat er Futures: A multivariat e analysis of populat ion growth and climat e change i mpacts on urban water demand in the Okanagan B asin, BC. Canadian Water Resources Journal, 32: 315-330. Nei lsen, D., Smith, C. A. S., Frank, G., Koch, W., Ali la, Y., Merrit t, W., Taylor, W. G., Bart on, M ., Hall, J. W. and Cohen, S. J. 2006. Potential imp act s of climate change on water availabilit y for crops in the Okanagan B asin, British Columbia. Can. J. Soil Science, 86:921-936. NeWater. New Approaches t o Adapt ive Wat er M anagement under Uncert ainty. [Accessible: ht tp://www.newat er.info] [Accessed 04/07/2008] Pul warty, R. and Melis, T., 2001: Climate extremes and adaptive management on t he Colorado River. J. Environmental Management, 63, 307-324 Pul warty, R., 2003: Cl imat e and water in t he West : Science, informat ion and decision making. Water Resources (Update), 124, 4-12 Pul warty, R., Jacobs, K., Dole, R., 2005: The hardest working river: Drought and crit ical water problems on the Colorado. In D. Wilhite (ed): Drought and Water Crises: Sci ence, Technology and M anagement . Taylor and Francis Press, 249-285. Pul warty, R., Simpson, C., and C., Nierenber g, 2009: The Regional Int egrated Scienc es and Assessments (RISA) Program: Crafting effective assessments for t he long haul. In Knight, C., and J., Jager, 2009 (eds.): Int egr at ed Regional Assessment of Climat e Change. Cambridge Universit y Press (in press). Sheppard, S .R.J. 2005. Landscape visualisat ion and climate change: The pot ential for influencing percept ions and behaviour. Environmental Science and Poli cy. 8, 637-654. Summi t Environmental Consult ants Limit ed. 2004. Trepanier Landscape Unit (Westside) water management plan. Regional Dist rict of Central Okanagan and British Columbia Ministry of Sust ainable Resource M anagement, Kelowna, 300 pp. Tansey, J., J. Carmichael, J., R. vanWynsberghe, R., and J. Robinson. 2002. The future is not what is used t o be: Part icipat ory integrated assessment in the Georgi a Basin. Global Environmental Change, 12, 97-104. US DoI 2007. Colorado River Interim Guidelines for Lower Basin Short ages and Coordinated Operations for Lakes Powell and Mead. Available from Bureau of Reclamation, 61 pp . ht tp ://www.usbr.gov/lc/region/programs/st rategies/RecordofDecision.pdf van den Be lt, M. 2004. Mediated Modeling: A System Dynamics Approach to Environmental Consensus Building. W ashingt on: Island Press.

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Yohe, G.W., R.D. Lasco, Q.K. Ahmad, N. Arnell, S.J. Cohen, C. Hope, A.C. Janetos and R.T. Perez. 2007. Perspectives on climate change and sustainabilit y. In: Climate Change 2007: Impacts, Adaptation, and Vulnerabili ty. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climat e Change [Parry, M., O. Canziani, J. Palut ikof and P. van der Linden (eds.)]. Cambridge University Press, Cambridge, Unit ed Kingdom and New York, NY, U SA, 811-841.

15

Climate Change and Water: Adaptation Stewart J. Cohen1 and Roger S. Pulwarty2 1University

of British Columbia, Vancouver, British Columbia, CANADA 2 National Oceanographic & Atmospheric Administration, Boulder, Colorado USA

Presented at Water Tribune Thematic Week 6—Climate Change and Extreme Events, EXPO ZARAGOZA 2008, July 24, 2008

Outline • Challenge of managing for multiple objectives within a scenario of climate change • Opportunity for participatory approaches • Climate change adaptation case studies: – Colorado Basin – Okanagan Basin

• Conclusions

Water Resources in the Columbia River Basin System objectives affected by winter flows Winter hydropower production (PNW demand) System objectives affected by summer flows Flood control Summer hydropower production (California demand) Irrigation Instream flow for fish Recreation Source: Alan Hamlet University of Washington

Columbia Basin Impacts of Climate Change on Streamflow • Less snow, earlier melt means less water in summer – – – –

irrigation urban uses fisheries protection energy production

• More water in winter – energy production – flooding Natural Columbia River flow at the Dalles, Oregon

Source: P. Mote, University of Washington

Percent of Control Run Climate

Climate change adaptation may involve complex tradeoffs between competing system objectives 2070-2098

140 PCM Control Climate and Current Operations

120

PCM Projected Climate and Current Operations

100

PCM Projected Climate with Adaptive Management

80 60 Firm Hydropower

Annual Flow Deficit at McNary Source: Barnett et al., 2005 (Nature).

The Leaky Boat & the Juggling Act

Participatory approach can help to build the science-policy bridge Role of local experts (practitioners, stakeholders) in climate change impacts-adaptation research Local context (planning, decision-making) Data, operational perspectives Professional networks Local governments

Experts become extension agents for local adaptation Role of research community changes from initiator of studies to resource for community-based assessments Broadens base of investments in impacts-adaptation research Potential for increased support for monitoring

Climate change information flow to stakeholders? Climate Information •Forecasts •Trends •Scenarios

ou tr

ea ch

Stakeholder Interest •Regional development •Jobs •Liability •Quality of life

Climate Change: The Medium is the Message

Filter / medium

Climate information delivery •Forecasts •Trends •Scenarios

•Hydrograph •Crop model •Malaria risk model •Decision support tool

Practitioner interest translation

•Risk assessment •Design standards •Operating rules •Allocations

……transl ……translation from climate science to practitioner interest

Participatory approach…link with practitioners (Cohen and Waddell, in press) Climate Information •Forecasts •Trends del ive

ou tr

ea ch

Filter / Medium •Hydrograph •Crop Model •Malaria Risk Model •Decision Support Tool

ry

ea ch

tr a ns la ti o n

•Scenarios

ou tr

Stakeholder Interest Practitioner Interest •Risk Assessment

extension

•Jobs

•Design Standards •Allocations

•Regional development •Liability

policy

•Quality of life

Building the science-policy bridge… • Dialogue with local experts/practitioners as part of integration; beyond serving as an information source and outreach process

Okanagan climate change study team visit to Penticton Dam, June 2002

Colorado Basin •Supplies water for 25 million people •By 2020, will need to support 38 million •Natural inflows have been below average in 7 of the last 9 years

Drought in the Colorado Basin: recent impacts and future scenarios • Below average runoff since 2000, accompanied by 0.8°C rise in temperature since 1950s – Increasing losses in snowpack, reduced soil moisture, increasing water demands – Initial allocations made during 1905-1925, a relatively wet period; this continues to influence management decisions

• Projected runoff decrease by 20% by 2050s, and 30% by end of 21st century (Milly et al., 2005) • Requirements of Colorado River Compact would be met only 60-75% by 2025 (Christensen et al., 2004)

Inclusion of stakeholders in the Colorado Basin water management has become the norm • National Integrated Drought Information System (NIDIS) created in 2006; result of ongoing drought conditions in Colorado Basin (www.drought.gov. ) – Coordinates information providers, users, monitoring, forecasting, risk and impact assessments, preparedness planning, and communication

Cross-scale issues in the integrated water management of the Colorado River Basin (Pulwarty and Melis 2001) Temporal Scale

Issue

Indeterminate

Flow necessary to protect endangered species

Long-term

Inter-basin allocation and allocation among basin states

Decade

Upper basin delivery obligation

Year

Coordinated Lake Powell -Lake Mead storage requirements

Seasonal

Peak heating and cooling months

Daily-monthly

Flood control operations

Hourly

Western Area Power Administration’s power generation

Spatial Scale Global

Climate influences, Grand Canyon National Park

Regional

Prior appropriation (e.g. Upper Colorado River Commission)

State

Different agreements on water marketing within and out of state water district

Munic ipal and Communities

Watering schedules, treatment, domestic use

Okanagan Basin – snowmelt watershed with semi-arid climate Supply depends on storage in • upland reservoirs • mainstem lakes • ground water (limited)

Photos: upper left—Kelowna and Okanagan Lake, lower left-Osoyoos and Osoyoos Lake (Denise Neilsen); right— installation of intake at Penticton, Okanagan Lake (Bob Hrasko)

Columbia Basin

Water Resources in the Okanagan Basin Part of the Columbia Basin, British Columbia CANADA -----------U.S.A.

Okanagan Basin

•Area = 8200 km2 •Okanagan Valley = 160 km in length •Population = 310,000 (1999 approx.); 13 municipalities, 3 regional districts, 4 First Nation communities, 59 “improvement districts” •Agriculture: fruit, vineyards, pasture; 40% irrigated lands; 3% decrease since 1976 due to urbanization

Okanagan-Similkameen British Columbia

Source: Cohen and Kulkarni (2001); map from Alan Hamlet (U. Washington)

Okanagan Basin, British Columbia •Rapid population growth •80% of streams fully recorded Populatio n growth in Central Okanagan, No rt h Okanagan and Ok anagan-Similkam een Regional District s: 1941-2001 (data from BC Stats and P.S. Ross & Partners; based on wor k by Shepher d)

Coquihalla Connector Completed

180,00 0 160,00 0

Population

140,00 0 120,00 0

Central Okanagan

100,00 0

Floating Bridge Completed

80,00 0

North Okanagan OkanaganSimilkameen

60,00 0 40,00 0 20,00 0

Year

2 000

1 995

1 990

1 985

1 980

1 975

1 970

1 965

1 960

1 955

1 950

1 945

0 1 940

Trout Creek

The 2003 Okanagan drought & fire Responding to future climate change & population growth?

6 5 4 3 2 1 0 1-Jan

1-M ar

1-May

1-Jul s2 0ca2

1-Sep s 50 ca2

4 3 2 1 1-M ar

1-May

base90

1-Jul s 20s a2

1-Sep s 50 sa2

4 3 2 1

4 3 2 1 0 1-J an

1-M ar

1-May

base90

1-Jul s 20ha2

1-Sep s 50ha2

1-Nov s 80ha2

s 50cb2

1-Nov s8 0cb2

5 4 3 2 1 0 1-J an

1-M ar

1-May

bas e90

1-Jul s2 0s b2

1-Sep s 50s b2

1-Nov s 80 sb2

Vas e aux Ck (above Dutton Ck) - HADLEY B2 Simulated Discharge (cumecs)

Simulated Discharge (cumecs)

5

s 20 cb2

1-Sep

6

Vas eaux Ck (above Dutton Ck) - HADLEY A2

6

1-Ju l

7

s8 0s a2

7

1-M ay

Vas eaux Ck (above Dutton Ck) - CSIRO B2

1-Nov

8

1-Mar

bas e9 0

Vas eaux Ck (above Dutton Ck) - CSIRO A2

5

0 1-Jan

5

s8 0ca2

6

Vas eaux Ck (above Dutton Ck) - CGCM2 B2

6

0 1-Jan

1-Nov



bas e90

7

7 Simulated Discharge (cumecs)


Vas eaux Ck (above Dutton Ck) - CGCM2 A2

8 7 6 5 4 3 2 1 0 1-Jan

1-Mar

1-M ay

bas e9 0

1-Ju l s 20hb2

1-Sep s50 hb2

1-No v s 80hb2

Streamflow Scenarios for Vaseux Creek (Merritt et al.)

7

Agricultural land use in the Okanagan Basin (photos from Denise Neilsen)

Risks associated with water supply and demand in response to climate change (Neilsen et al., 2004)

Maximum allowable demand – 2002 use

Trout Creek supply/demand CGCM2-B2

2020s

10

2050s 2080s

8 6 4 2

6

12

14 12

2020s

3

Histo ric

10

2050s

Crop water demand (m x 10 )

14

3

6

Cro p w at er dem and (m x 10 )

Trout Creek supply/demand HadCM3-A2

Historic

2080s 8 6 4 2 0

0 0

50

100

150 3

200

250

6

Annual flow (m x 10 )

Local defined drought – 30% average annual flow

0

50

100

150 3

200 6

Annual flow ( m x 10 )

250

Domestic Demand Side Management Oliver, CGCM2 A2, Medium Population Growth (Neale et al, 2007)

8000 7000

2001 Baseline Current DSM Education Metering CUC Metering IBR Xeriscaping

5000 4000 3000

High Eff Retrofit

Combined

2000 1000

Year

2069

2065

2061

2057

2053

2049

2045

2041

2037

2033

2029

2025

2021

2017

2013

2009

2005

0 2001

Water Demand (ML)

6000

Okanagan adaptation costs, based on recent & proposed water projects (source: McNeill & Hrasko, 2006) Component

Annual ML Developed

Mainstem

8300

$

947,381

$

114

GW

1250

$

258,060

$

206

Mainstem

3000

$

755,798

$

252

WT

12775

$

3,780,000

$

296

Watershed

1850

$

773,548

$

418

WT

12775

$

5,541,618

$

434

Conserv.

2925

$

1,318,362

$

451

Conserv.

1760

$

1,050,155

$

597

Watershed

2096

$

1,944,000

$

927

1b Lakeview Irrigation District - 1993 Big Horn Dam (to full pool in 1993)

Watershed

3400

$

3,141,882

$

924

7

Mainstem

6400

$

6,268,388

$

979

1a Lakeview Irrigation District - 1993 Big Horn Dam (existing)

Watershed

2295

$

2,356,412

$

1,027

6

Mainstem

3494

$

4,802,816

$

1,375

Watershed

1105

$

1,643,532

$

1,487

12 City of Kelowna - Domestic Metering Program

Conserv.

2900

$

5,822,097

$

2,008

5

moderate

8100

$ 17,743,839

$

2,191

Conserv.

266

$

665,451

$

2,502

16 City of Penticton - WTP Conventional Filtration

WT

7300

$ 20,389,697

$

2,793

17 Westbank Irrigation District - Infilter DAF

WT

6570

$ 18,600,000

$

2,831

18 City of Kamloops - Membrane Filtration

WT

19467

$ 58,060,800

$

2,983

19 Lakeview Irrigation District - DAF Filtration WTP (proposed)

WT

5475

$ 17,015,806

$

3,108

20 Lakeview Irrigation District - Actiflo-Filtration WTP (proposed)

WT

5475

$ 18,006,311

$

3,289

21 Lakeview Irrigation District - Conventional WTP (proposed)

WT

5475

$ 18,173,030

$

3,319

Watershed

4600

$ 22,944,641

$

4,988

WT

5475

$ 30,966,849

$

5,656

# PROJECTS ( Listed by $ / ML ) 8

City of Penticton - Okanagan Lake Intake Pipe

13 Glenmore-Ellison Improvement District - Airport Well No. 2 9

District of Salmon Arm - Canoe Lake Intake Pipe

14 City of Kelowna - UV Disinfection 3

Black Mountain Irrigation District - Mission Lake Reservoir (proposed)

15 Black Mountain Irrigation District - WTP Clarification Only 10a South East Kelowna Irrigation District - Irrigation Metering Program 11 Black Mountain Irrigation District - Irrigation Metering Program (proposed) 2

South East Kelowna Irrigation District - Turtle Lake Expansion (proposed)

Glenmore-Ellison Improvement District - Okanagan Lake Supply (proposed)

District of Summerland - Trout Creek Pump Station ( proposed)

1c Lakeview Irrigation District - 2005 Big Horn Dam expansion

Lakeview Irrigation District - Lambly Creek Dam ( proposed )

10b South East Kelowna Irrigation District - Domestic Metering ( proposed )

4

Black Mountain Irrigation District - Black Mountain Reservoir (proposed)

22 Lakeview Irrigation District - Membrane Filtration WTP (proposed)

$ / ML

TOTAL COST

GW = groundwater Watershed = supply expansion WT = water treatment Conserv. = manage demand

Impact on Okanagan Water Management • Incorporation of climate change into Trepanier Landscape Unit Water Management Plan – Recommends demand management as first priority, along with supply augmentation, by 2050 if no climate change assumed, and by 2020 if climate change is assumed

Moving Beyond The Damage Report an opportunity for participatory integrated assessment (PIA) & decision support….

+ Technical Info & Data

= Experience Based Knowledge & Values

Decision Support Model

Preliminary sketch of decision model (Langsdale et al., 2006, 2007)

Okanagan Surfacewater Supply Evaporating

Tributaries Inflowing

Human Use Diverting

Precipitating on Lakes

Agricultural Demand

Flowing Out of Basin Residential Demand

U.S. Border C & I Demand

Input from some participants at Okanagan study model building workshop, April 2005 (Cohen & Neale, 2007)

2040-2069 case; Upland agriculture supply-demand balance, (1) No adaptation; (2)adaptation DSM & densification implemented

2040-2069 case; Agriculture supply-demand balance; (1) No adaptation; (2) supplement with Okanagan Lake; no other adaptation

2040-2069 case; climate change & high population growth; Uplands instream allocation